ch 16 Jarvis Ears Flashcards
the external ear, the middle ear, and the inner ear
three parts of ear
is called the auricle or pinna and consists of movable cartilage and skin
external ear
serves to funnel sound waves into its opening
-terminates at the eardrum, or tympanic membrane (TM)
external auditory canal
is lined with glands that secrete cerumen, a yellow, waxy material that lubricates and protects the ear.
canal (of the external auditory canal)
forms a sticky barrier that helps keep foreign bodies from entering and reaching the sensitive tympanic membrane.
wax
migrates out to the meatus by the movements of chewing and talking.
Cerumen (waxy stuff)
separates the external and middle ear and is tilted obliquely to the ear canal, facing downward and somewhat forward. It is translucent with a pearly gray color and a prominent cone of light in the anteroinferior quadrant, which is the reflection of the otoscope light
tympanic membrane (TM)
is oval and slightly concave, pulled in at its center by one of the middle ear ossicles, the malleus
drum
; these are the umbo, the manubrium (handle), and the short process.
parts of the malleus show through the translucent drum
small, slack, superior section of the TM is called the
pars flaccida (part of tm)
remainder of the drum, which is thicker and more taut, is the
pars tensa(part of tm)
is the outer fibrous rim of the drum
annulus(part of tm)
flows to the parotid, mastoid, and superficial cervical nodes.
Lymphatic drainage of the external ear
is a tiny air-filled cavity inside the temporal bone
middle ear
the malleus, incus, and stapes
-outer ear is covered by the tympanic membrane
tiny ear bones, or auditory ossicles (middle ear)
are the oval window at the end of the stapes and the round window
openings to the inner ear
Another opening is? , which connects the middle ear with the nasopharynx and allows passage of air
- tube is normally closed, but it opens with swallowing or yawning.
- Retracted drum due to vacuum in middle ear with obstructed eustachian tube
the eustachian tube
(1) it conducts sound vibrations from the outer ear to the central hearing apparatus in the inner ear;
(2) it protects the inner ear by reducing the amplitude of loud sounds;
(3) its eustachian tube allows equalization of air pressure on each side of the tympanic membrane so the membrane does not rupture (e.g., during altitude changes in an airplane)
middle ear has three functions
, which holds the sensory organs for equilibrium and hearing
bony labyrinth (inner ear)
Within the bony labyrinth, the vestibule and the semicircular canals comprise the ?, and the cochlea
vestibular apparatus (inner ear)
contains the central hearing apparatus
cochlea (inner ear)
, the bony prominence behind the lobule, is not part of the ear but is an important landmark.
mastoid process
peripheral, brainstem, and cerebral cortex
function of hearing involves the auditory system at three levels:
the ear transmits sound and converts its vibrations into electrical impulses, which can be analyzed by the brain
peripheral level
is how loud
amplitude
is the pitch
-number of cycles per second
frequency
, the sensory organ of hearing
organ of Corti
- tympanic meme
- stapes embedded in oval window
- basilar membrane of cochlea contain organ of corti hair cells
pathway of hearing
loss involves a mechanical dysfunction of the external or middle ear
- caused by impacted cerumen, foreign bodies, a perforated tympanic membrane, pus or serum in the middle ear, and otosclerosis (a decrease in mobility of the ossicles)
- partial loss because the person is able to hear if the sound amplitude is increased enough to reach normal nerve elements in the inner ear
conductive hearing
loss signifies pathology of the inner ear, cranial nerve VIII, or the auditory areas of the cerebral cortex
-simple increase in amplitude may not enable the person to understand words
Sensorineural (or perceptive)
hearing loss may be caused by presbycusis, a gradual nerve degeneration that occurs with aging, and by ototoxic drugs, which affect the hair cells in the cochlea.
Sensorineural (or perceptive)
, in the inner ear constantly feed information to your brain about the position of your body in space
-work like plumb lines to determine verticality or depth
3 semicircular canals, or labyrinth (equilibrium)
of the ear register the angle of your head in relation to gravity.
plumb lines(equilibrium)
labyrinth ever becomes inflamed, it feeds the wrong information to the brain, creating a staggering gait and a strong spinning, whirling sensation called
vertigo.(equilibrium)
inner ear starts to develop early in the
5th week of gestation
occurs during the 1st trimester, it can damage the organ of Corti and impair hearing.
maternal rubella infection
is relatively shorter and wider, and its position is more horizontal than the adult’s; thus it is easier for pathogens from the nasopharynx to migrate through to the middle ear. The lumen is surrounded by lymphoid tissue, which increases during childhood; thus the lumen is easily occluded. = high rick for child gain ear infection
infant’s eustachian tube
are shorter and have a slope opposite to that of the adult’s.
infant’s and the young child’s external ear canals
is a cause of conductive hearing loss in young adults between the ages of 20 and 40 years. It is a gradual bone formation that causes the footplate of the stapes to become fixed in the oval window, impeding the transmission of sound and causing progressive deafness.
Otosclerosis
cilia lining the ear canal become coarse and stiff.
- cause cerumen to accumulate and oxidize, which greatly reduces hearing
Aging Adult
also blocks conduction in those wearing hearing aids.
Cerumen impaction
are wax-softening agents that expedite removal with electric or manual irrigators
Ceruminolytics
sensorineural loss that affects the middle ear structures or causes damage to nerve cells in the inner ear or to cranial nerve VIII. The person first notices a high-frequency tone loss, such as difficulty hearing a phone ringing
-hearing loss is accentuated with competing background noise
Age-related hearing loss (presbycusis)
affects men more than women of the same age, and there is a lower prevalence among African Americans compared with whites or Hispanics.
- current theories relate to melanin pigment protection in the cochlea or other environmental factors
Presbycusis
, occurs because of obstruction of the eustachian tube or passage of nasopharyngeal secretions into the middle ear.
- 1-3yrs old
- risk fact: absence of breastfeeding in the first 3 months of age, preterm birth, exposure to secondhand tobacco smoke (SHS), daycare attendance, male sex, pacifier use, seasonality (fall and winter), and bottle-feeding
- sticky, yellow discharge
- drum has ruptured.
- Redness and swelling occur with otitis externa; canal may be completely closed with swelling.
Otitis media, or OM (middle ear infection)
is genetically determined, with two distinct types. Wet, honey-brown wax occurs in Caucasians and African Americans, and a dry, flaky white wax is found in East Asians and American Indians
Cerumen
occurs directly from ear disease or is referred pain from a problem in teeth or oropharynx.
Otalgia
suggests infected canal or perforated eardrum such as
External otitis—Purulent, sanguineous, or watery discharge.
Acute OM with perforation—Purulent discharge.
Otorrhea
—Dirty yellow-gray discharge, foul odor.
Cholesteatoma
—Ear pain occurs first, stops with a popping sensation; then drainage occurs.
- shows as a dark oval area or as a larger opening on the drum.
perforation
is gradual onset over years, bilateral, mostly high-frequency loss, worse in noisy environments, whereas a trauma hearing loss is often sudden
Presbycusis
—A hearing loss with low-intensity speech, but sound actually becomes painful when speaker repeats in a loud voice.
Recruitment
Person lip-reads or watches your face and lips closely rather than your eyes
- Frowns or strains forward to hear
- Postures head to catch sounds with better ear
- Misunderstands your questions or frequently asks you to repeat
- Acts irritable or shows startle reflex when you raise your voice (recruitment)
- Person’s speech sounds garbled, possibly vowel sounds distorted
- Inappropriately loud voice
- Flat, monotonous tone of voice
indicate unreported hearing loss
is the perception of sound without an external source1a; it occurs with sensorineural hearing loss, cerumen impaction, middle ear infection, and other ear disorders.
- ringing, roaring, buzzing in ear
- cause sleep disturbance, depression, or anxiety and be so debilitating that person cannot lead a normal life
Tinnitus
aminoglycoside antibiotics and the anticancer drug cisplatin (loss in 60% to 65% of patients).
2 Also possibly furosemide, vancomycin, and chronic use of aspirin.
ototoxic drugs
is the most common type of vertigo, with brief (<1 minute) spinning sensations. Occurs with dysfunction of labyrinth. Increases risk for falls and doing daily activities.5 Feeling of spinning of person (subjective vertigo) or of objects around person (objective vertigo).
Benign paroxysmal positional vertigo
first episode within 3 months of life increases risk for
-infants (ear infection)
recurrent OM.
is 3 episodes in past 3 months or 4 within past year.
Recurrent OM
: those exposed to maternal rubella or maternal ototoxic drugs in utero; premature infants; low-birth-weight infants; trauma or hypoxia at birth; and infants with congenital liver or kidney disease
-incidence of meningitis, measles, mumps, OM, and any illness with persistent high fever may
Children at risk for hearing deficit
—ears larger than 10 cm
macrotia
—ears smaller than 4 cm vertically
Microtia
, a small, painless nodule at the helix. This is a congenital variation
Darwin tubercle
Red-blue discoloration with swelling of auricle after exposure to extreme cold. Vesicles or bullae may develop, the person feels pain and tenderness, and ear necrosis may ensue.
frostbite. (
External Ear Abnormalities)
Pain at the mastoid process may indicate
mastoiditis or enlarged posterior auricular node.
Pull the pinna down on an infant and a child younger than 3 years
-Pull the pinna up and back on an adult or older child; this helps straighten the S-shape of the canal
Inspect with the Otoscope
Purulent otorrhea suggests
- pinna and tragus, redness and swelling of pinna and canal, scanty purulent discharge, scaling, itching, fever, and enlarged tender regional lymph nodes.
- More common in hot, humid weather. Swimming causes canal to become waterlogged and swell; skinfolds set up for infection. Prevent by using rubbing alcohol or 2% acetic acid eardrops after every swim
otitis externa (Swimmer’s Ear)//External Ear Abnormalities
Frank blood or clear, watery drainage (cerebrospinal fluid [CSF]) after head injury suggests
basal skull fracture
Yellow-amber drum color occurs with OM with effusion (serous).
Red color with acute OM.
Absent or distorted landmarks
-Bulging drum due to increased pressure
-Ear pain and ear rubbing are associated with acute OM, as are a bulging red eardrum and middle ear effusion. Fever is usually present but not always
OM
gives a precise quantitative measure of hearing by assessing the person’s ability to hear sounds of varying frequency.
pure tone audiometer
person is unable to hear whispered items. A whisper is a high-frequency sound and is used to detect high-tone loss.
-passing score is correct repetition of 4 of a possible 6 numbers/letters. Assess the other ear using yet another set of whispered items “4, K, 2.”
Whispered Voice Test
measure hearing by air conduction (AC) or bone conduction (BC), in which the sound vibrates through the cranial bones to the inner ear. The AC route through the ear canal and middle ear is usually the more sensitive route. If hearing loss is identified by history or whispered voice test, tuning fork tests traditionally were used to distinguish conductive loss from sensorineural loss
-tests may help distinguish conductive loss from sensorineural loss. But they cannot screen a conductive loss from a mixed conductive/sensorineural loss.
Tuning fork tests
is more accurate in detecting conductive hearing loss.
Rinne test
assesses the ability of the vestibular apparatus in the inner ear to help maintain standing balance. Because the Romberg test also assesses intactness of the cerebellum and proprioception
Romberg test
=—Absence or closure of the ear canal.
Atresia
position of the eardrum is more horizontal in the neonate, making it more difficult to see completely and harder to differentiate from the canal wall.
by 1 month of age the drum is in the oblique (more vertical) position as in the older child, and examination is a bit easier
infant exam
attachment enables you to direct a light puff of air toward the drum to assess vibratility
pneumatic bulb (infant/child)
indicates effusion or a high vacuum in the middle ear. For the newborn’s first 6 weeks, drum immobility is the best indicator of middle ear infection.
Drum hypomobility
tympanostomy tube in the central part of the eardrum. This is inserted surgically to equalize pressure and drain secretions.
Chronic OM relieved
—Startle (Moro) reflex, acoustic blink reflex
Newborn (Test Hearing Acuity.)
—Acoustic blink reflex, infant stops movement and appears to “listen,” stops sucking, quiets if crying, cries if quiet
3 to 4 months(Test Hearing Acuity.)
—Infant turns head to localize sound, responds to own name
6 to 8 months(Test Hearing Acuity.)
—Child must be screened with audiometry
Preschool and school-age child
will be checked before the baby leaves the hospital or during the first month of life
newborn (1 month of life) baby’s hearing
who do not pass the hearing screening should be scheduled immediately for a follow-up appointment with a pediatric audiologist. This examination must happen by age 3 months.
3 = All infants (baby’s hearing)
If the follow-up examination confirms that the baby has hearing loss, the baby must receive appropriate interventions by ? months of age, including hearing devices and early communication intervention (e.g., lipreading, signed English, American Sign Language, or others).
6 months of age
Two different tests are used for newborn hearing screening
-The baby can rest or sleep during both tests; each test takes 5 to10 minutes.
(1) otoacoustic emissions (OAE) test
2) auditory brainstem response (ABR
—for this test a soft probe is placed just inside the baby’s ear canal to measure the response (echo) when clicks or tones are played into the baby’s ears,
otoacoustic emissions (OAE) test
—clicks or tones are played through soft earphones placed over the baby’s ears while electrodes placed on the baby’s head measure how the auditory nerve and brainstem carry sound from the ear to the brain
auditory brainstem response (ABR)
facial remnant or leftover of the embryologic branchial arch usually appears as a skin tag; in this case, one containing cartilage. Occurs most often in the preauricular area, in front of the tragus. When bilateral, there is increased risk for renal anomalies.
Branchial Remnant and Ear Deformity
External Ear Abnormalities
Inflammation of loose, subcutaneous connective tissue. Shows as thickening and induration of auricle with distorted contours
Cellulitis(External Ear Abnormalities)
Painful nodules develop on rim of helix (where there is no cushioning subcutaneous tissue) as a result of repetitive mechanical pressure or environmental trauma (sunlight). They are small, indurated, dull red, poorly defined, and very painful.
Chondrodermatitis Nodularis Helicus/ (Lumps and Lesions on the Ear)
Trauma to the side of the head may lead to a basilar skull fracture involving the temporal bone. This shows as ecchymotic discoloration just posterior to the pinna and over the mastoid process. A look inside the ear canal may show hemotympanum as well
Battle Sign/ (Lumps and Lesions on the Ear)
Location is commonly behind lobule in the postauricular fold. A nodule with central black punctum indicates blocked sebaceous gland. It is filled with waxy sebaceous material and painful if it becomes infected. Often are multiple.
Sebaceous Cyst / (Lumps and Lesions on the Ear)
Small, whitish yellow, hard, nontender nodules in or near helix or antihelix; contain greasy, chalky material of uric acid crystals and are a sign of gout.
Tophi/ (Lumps and Lesions on the Ear)
Overgrowth of scar tissue, which invades original site of trauma. It is more common in darkly pigmented people, although it also occurs in whites. In the ear it is most common at lobule at site of a pierced ear. Overgrowth shown here is unusually large.
Keloid/ (Lumps and Lesions on the Ear)
Ulcerated, crusted nodule with indurated base that fails to heal. Bleeds intermittently. Must refer for biopsy. Usually occurs on the superior rim of the pinna, which has the most sun exposure. May occur also in ear canal and show chronic discharge that is either serosanguineous or bloody
Carcinoma/ (Lumps and Lesions on the Ear)
Produced or is impacted because of narrow, tortuous canal or poor cleaning method. May show as round ball partially obscuring drum or totally occluding canal.
-when cerumen expands after swimming or showering), person has ear fullness and sudden hearing loss.
Excessive Cerumen (Ear Canal Abnormalities)
Severe swelling of canal, inflammation, tenderness. In the figure above, canal lumen is narrowed to one-fourth normal size.
Otitis Externa ( Ear Canal Abnormalities)
Common objects are beans, corn, breakfast cereals, jewelry beads, small stones, sponge rubber. Cotton is most common in adults and becomes impacted from cotton-tipped applicators. A trapped live insect is rare but makes the person especially frantic.
Foreign Body (children place)// ( Ear Canal Abnormalities)
Single, stony hard, rounded nodule that obscures the drum; nontender; overlying skin appears normal. Attached to inner third, the bony part, of canal. Benign, but refer for removal.
Osteoma// (
Ear Canal Abnormalities)
More common than osteoma. Small, bony hard, rounded nodules of hypertrophic bone, covered with normal epithelium. Arise near the drum but usually do not obstruct the view of the drum. Usually multiple and bilateral, occur more frequently in cold-water swimmers. Needs no treatment, although may cause accumulation of cerumen, which blocks the canal.
Exostosis/ (Ear Canal Abnormalities)
Arises in canal from granulomatous or mucosal tissue; redder than surrounding skin and bleeds easily; bathed in foul, purulent discharge; indicates chronic ear disease. Benign but refer for excision.
Polyp/ (Ear Canal Abnormalities)
Exquisitely painful, reddened, infected hair follicle. It may occur on tragus on cartilaginous part of ear canal. Regional lymphadenopathy often accompanies a furuncle.
Furuncle/ (Ear Canal Abnormalities)
Landmarks look more prominent and well defined. Malleus handle looks shorter and more horizontal than normal. Short process is very prominent. Light reflex is absent or distorted. The drum is dull and lusterless and does not move. These signs indicate negative pressure and middle ear vacuum from obstructed eustachian tube and serous otitis media
Retracted Drum// (
Abnormal Tympanic Membranes)
amber-yellow drum suggests serum in middle ear that transudes to relieve negative pressure from the blocked eustachian tube. You may note an air/fluid level with a fine black dividing line or air bubbles visible behind drum. Symptoms are feeling of fullness, transient hearing loss, popping sound with swallowing. Also called serous otitis media, glue ear.
Otitis Media With Effusion (OME)// (
Abnormal Tympanic Membranes)
This results when the middle ear fluid is infected. An absent light reflex from increasing middle ear pressure is an early sign. Redness and bulging are first noted in superior part of drum (pars flaccida), along with earache and fever. Then fiery red bulging of entire drum occurs along with deep throbbing pain. Accompanied by possible fever and transient hearing loss. Pneumatic otoscopy reveals drum hypomobility.
Acute Otitis Media// (
Abnormal Tympanic Membranes)
acute otitis media is not treated, the drum may rupture from increased pressure. Perforations also occur from trauma (e.g., a slap on the ear). Usually the perforation appears as a round or oval darkened area on the drum. Central perforations occur in the pars tensa. Marginal perforations occur at the annulus. Marginal perforations are called attic perforations when they occur in the superior part of the drum, the pars flaccida.
Perforation// (
Abnormal Tympanic Membranes)
overgrowth of epidermal tissue in the middle ear or temporal bone may result over the years after a marginal TM perforation. It has a pearly white, cheesy appearance. Growth of cholesteatoma can erode bone and produce hearing loss. Early signs include otorrhea, otalgia, unilateral conductive hearing loss, tinnitus.
Cholesteatoma/ (
Abnormal Tympanic Membranes)
Polyethylene tubes are inserted surgically into the eardrum to relieve middle ear pressure and promote drainage of chronic or recurrent middle ear infections. Number of acute infections tends to decrease because of improved aeration. Tubes extrude spontaneously in 12 to 18 months.
Insertion of Tympanostomy Tubes/ (
Abnormal Tympanic Membranes)
Colony of black or white dots on drum or canal wall suggests a yeast or fungal infection.
Fungal Infection (Otomycosis)// ( Abnormal Tympanic Membranes)
Dense white patches on the eardrum are sequelae of repeated ear infections. They do not necessarily affect hearing.
Scarred Drum // (
Abnormal Tympanic Membranes)
blood in the middle ear, as in trauma resulting in skull fracture
Blue Drum (Hemotympanum)// (Abnormal Tympanic Membranes)
Small vesicles containing blood are on the eardrum; it accompanies mycoplasma pneumonia and viral infections. Blood-tinged discharge and severe otalgia may be present.
Bullous Myringitis// (Abnormal Tympanic Membranes)
